In earlier technology, in a portable information technology device, such as a PDA (Personal Digital Assistant; an individual portable information terminal) or the like, a pen-input type display device which is constituted with a display unit, such as a liquid crystal display panel which is constituted integrally with a touch type sensor, and a pen input unit, such as a stylus pen or the like, is widely used as devices which perform a man-machine interface.
This is because the pen-input type display device can be operated easily even if it is a user who does not have high skill. Further, it is because the pen-input display unit can be provided cheaply since the internal mechanism of the pen-input type display device is comparatively easy configuration.
Incidentally, as shown in FIG. 13, in a PDA 400, as a method for inputting data, such as characters, patterns or the like, there is a method of selecting a pattern or character defined as a software keyboard 22 displayed on a liquid crystal display panel 21, by a pen 23, or a method of writing directly a character or pattern or the like on a predetermined input area 24 of the liquid crystal display panel 21 with the pen 23.
Further, for inputting large quantity of data, as an extended input unit of the pen-input type display device, a keyboard in which an electronic circuit is built in is used by connecting to the PDA 400 with a cable or the like.
However, there were the following problems in the data input method by the pen-input type display device which is carried in the above PDA 400 in earlier technology.
The method of clicking a pattern or character defined as the software keyboard 22 displayed on the liquid crystal display panel 21, with the pen 23 is not suitable for inputting large quantity of data because it takes time to input the data. Moreover, in the liquid crystal display panel 21, since the display area of the software keyboard 22 becomes large, the area for carrying out other applications becomes narrow. Therefore, operationality will deteriorate.
The method of inputting a character or pattern or the like by writing it directly on the predetermined input area 24 is not suitable for inputting large quantity of data because it takes time to input the data. Further, since the capacity of program which recognizes the character from the inputted data becomes large, the capacity of memory which is to be built in the PDA 400 becomes large. Therefore, there was a problem that the manufacturing cost of the PDA 400 would be raised.
Further, because of structural defects of the keyboard used as an extended input unit of a pen-input type display device, it was difficult for lightening and miniaturizing the keyboard. Therefore, it was difficult to carry the keyboard with the PDA 400.
It is an object of the present invention to provide a key-board type auxiliary input mechanism which is suitable for inputting large quantity of data to a portable information technology device having a pen-input type display device.